Carboxylic acid nitriles



Patented Jan. 6, 1942 UNITED STATE CABBOXYLIO ACID m'rmms I Winlrid Bentrleh, Bodleben, near Deccan-lossllll, and Reins-Joachim Germany, amignora Aktiengeaellachait.

Engelbrecht, Deasan, Dentache Bydrlerwerke Berlin Gharlottenbnrg,

Germany, a corporation of Germany No mam. Application m n s, 194, Serial No. 822,342. In Germany November 1, 193.8

Claims. (CL 260-464) It has been found that we can produce the nitriles of carboxylic acids in a simple way by treating carboxylic acid amides with trichloromethylchioroiormate. The conversion is eflected by warming the carboxylic acid amides preferably in the presence of a suitable volatile solvent or diluent such as benzol, toluol, benzine, chlorohydrocarbons, ethers. etc. together with the chloro-iormiate oi the trichloro-methyl alcohol. It is generally suflicient to use 1 mol of the formic acid ester tor 2 mols of mono- Y carboxylic acid amide. However, we may likewise use an excess of the ester.

' The conversion is accompanied by an evolution 01 gas and it is continued until thisevolution of gas practically-stops.- At flrst. in applying this method, we;work at low temperatures, e. g. between and45 C. and finally we continue the heating for a while on a reflux condenserto flnish the conversion.

We use as raw materials in our process monoor polycarboxylic acid amides oi the aliphatic, cycloaliphatic or aromatic series or their mixtures. They may contain straight-chained or branched-chained hydrocarbon residues. E. g. we may use aceticacid amide, butyric acid amide, capric acid amide. lauric acid amide, oleic acid amide, stearic acid amide, montanic acid amide, naphthenic acid amides, resinic acid amides, adipic acid diamide, benzamide and its substitution products, phthalicacid diamide, anthraquinone-Z-carboxylic acid amide, tetrahydrophthalic acid. diamide, hexahydrophthalic acid diamide, cyclohexane-diacetic acid diamide and the like. The hydrocarbon residues of these carboxylic acid amides may also contain hetero atoms or hetero atom groups such as oxygen, sulfur, nitrogen or halogen as well as ester groups and other acid amide groups. Mixed carboxylic acid amides may be converted with trichloromethylchloroiormate also.

The carboxylic acid nitriles obtained according to the present method are valuable initial products for chemical conversions. For example, some may be used in the preparation of capillary active compounds, while others in the arcmatic series-are valuable intermediate productsfor the production of dyestufl's.

The following examples serve to illustrate the described method for the manufacture oi carbox- 1 yllc acid nitriles, but they are not intended to limit it thereto; the parts being by weight:

freampzez".

'rwo hundred weighty-three we oi etearlc as acid amide (technically pure) and 110 parts of chloro-formiate of the trichloro-methyl alcohol are warmed in the presence of 1000 parts oi benzene up 'to a temperature of -40 0., whereat an evolution or gas will be observed. The conversion is completed while slowly raising the temperature and flnallyby a short boiling on the reflux condenser. Now the solvent is distilled of! after entirely expelling the developed hydrochloric acid gas and the residue to be free of chlorine is then distilled under reduced pressure. We thus obtainthe stea'ric acid nitrile (boiling point 150 to 156 C. at 1.5 mmpressure of mercury) with a yield of 95%.

In a similar way we obtain the benzonitrile from benzamide and the 1,2-dicyanobenzol irom phthalic acid-dia'mide.

Example 2 To a suspension consisting of 36 parts of adipic acid amide in 200-parts oi 'gxylol, 55 parts of chloro-iormic acid-trichloro-methyl ester are added. While warming up to 40-600. the evolution of gas will set in. The temperature is now slowly raised and regulated in proportion to the amount 01 gas evolved. By boiling on the reflux condenser the reaction is completed. When the solvent is distilled ofl the residue resulting at the distillation under reduced pressure is the adipic acid-dinitrile in the form of a colourless oil. Its boiling point is 150 C. at a mercury pressure of 11 mm.

Whatweclaim is:

1. The process of producing a nltrile of-a carboxylic acid comprising reacting a carboxylic methyl alcohol.

2. The process of producing a nitrile' ot a carboxylic acid comprising reacting a qarbcxylic acid amide with trichloromethylchloroformate in the presence of a volatile liquid. V

3. The process of producing a nitrile of a carboxylic' acid comprising reacting a dicarboxylic acid amide with trichloromethylchloroiormate.

4. The process 01' producing a nitrile 01' a car boxylic acid which comprises heating a" carboxylic acid amide with trichloromethylchloroiormate until an evolution of gas has substantially ceased.

5. The process of producing a nitrile oi a carboxylic acid which comprises reactingan aliphatic carboxylic acid amide with trichloromethylchloroiormate; & i-

EIINZ-JOACBIM ENG.

acid amide with the chloro-iormiate oi trichloro-. 

